Which of the following explains why selection can cause populations of organisms to change?
a. It teaches organisms how to survive better in their environments. b. It allows some organisms to survive and produce offspring while others do not.
c. It causes changes in organisms to help them in their everyday lives.
d. It chooses certain organisms with good traits over other organisms with bad traits.

1. an enzyme is considered a(n) because it speeds up a chemical reaction without being used up.2. in a catalyzed reaction, a reactant is often called a(n) . an enzyme is specific because the shape of its matches only particular reactants.4. an enzyme speeds up reactions by lowering the . the between an active site and its substrate often strains bonds and the reaction proceed.6. a( , which is often a vitamin, binds to an enzyme and plays a role in catalysis.7. high temperatures or changes in ph can an enzyme, causing it to lose its shape and biological activity.